From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugs-return-116714-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 16444 invoked by alias); 1 Nov 2004 02:34:37 -0000
Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Archive: <http://gcc.gnu.org/ml/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-help@gcc.gnu.org>
Sender: gcc-bugs-owner@gcc.gnu.org
Received: (qmail 16428 invoked by uid 48); 1 Nov 2004 02:34:36 -0000
Date: Mon, 01 Nov 2004 02:34:00 -0000
Message-ID: <20041101023436.16427.qmail@sourceware.org>
From: "pinskia at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
In-Reply-To: <20041031010322.18241.ak@muc.de>
References: <20041031010322.18241.ak@muc.de>
Reply-To: gcc-bugzilla@gcc.gnu.org
Subject: [Bug tree-optimization/18241] [4.0 Regression] linux kernel loop gets miscompiled
X-Bugzilla-Reason: CC
X-SW-Source: 2004-11/txt/msg00123.txt.bz2
List-Id: <gcc-bugs.sourceware.org>


------- Additional Comments From pinskia at gcc dot gnu dot org  2004-11-01 02:34 -------
Also for the first loop, we look we do much worse code with -fivopts at least on powerpc64:
With -fno-ivopts:
  offset = (int) (unsigned int) (index >> (int) shift) & 63;
  pathp = pathp.109 + 24B;
  pathp->offset = offset;
  temp.107 = *pathp.109->slot;
  pathp->node = temp.107;
  D.7848 = (struct radix_tree_node * *) &temp.107->slots + (void * *) ((long unsigned int) offset * 8);
  pathp->slot = D.7848;
  shift = shift - 6;
  height = height - 1;

without:
  offset = (int) (unsigned int) (index >> (int) (shift + (unsigned int) ivtmp.126 * 4294967290)) & 63;
             <--- here why not keep the shift decrementing
  pathp.155 = ivtmp.137 + &path + 24B;
  D.8017 = &path + 24B;
  *((int *) ivtmp.137 + &D.8017->offset) = offset;
  D.8020 = (struct radix_tree_node * * *) ivtmp.137;
  temp.162 = **(D.8020 + &path[0].slot);
  *((struct radix_tree_node * *) ivtmp.137 + &D.8017->node) = temp.162;
  D.7848 = (struct radix_tree_node * *) &temp.162->slots + (void * *) ((long unsigned int) offset * 8);
  *(D.8020 + &D.8017->slot) = D.7848;
  height = height + 4294967295;

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18241